Method of preventing offsets



Aug, 8, 1933. E. c. FRANCOISE 1,921,313

METHOD OF PREVENTING OFFSETS Original Filed July 29, 1929 IN VE N TOR IEdward Cflmnca/se BY v Patented Aug 8, i933 METHQD 01F PREVENTINGQFFSE'ES Edward C. Francoise, Parchment, Mich, assignor to KalamazooVegetable Parchment Company,

Kalamazoo, Mich.

()riginal application July 29, 1929, Serial No. 382,046. Divided andthis application March 3 Glaims.

This application is a division of my application for Letters PatentSerial No. 382,046, filed July 29, 1929 and now Patent No. 1,845,260,

dated February 16, 1932.

The main object of this invention is to provide a method of preventingoffsets in printing which permits winding very quickly after printing,thereby avoiding the necessity for long drying reaches.

Objects pertaining to details and economies of my invention willdefinitely appear from the description to follow. The invention isdefined in the claims.

The manner of carrying out my invention is clearly illustrated in theaccompanying drawing, in which:

Fig. 1 is a diagrammatic view of a printing and treating apparatusemployed by me for the practice of my invention in the manufacture ofwaxed paper.

Fig. 2 is an enlarged fragmentary section through the offset waxapplying and chilling means.

In Fig. l I illustrate diagrammatically the steps of my improved method.1 represents the roll of paper to be printed, 2 the printing machine and3 the printed roll. Intermediate the printed roll and printing machine Iarrange an apparatus for applying liquid parafiin or other suitable waxto the reverse or unprinted side of the web of paper, this apparatusconsisting of a wax applying roll 4 which dips into a tank 5, a doctoror distributing blade 6 being provided for the roll.

Immediately at the rear of the wax applying roll is a chilling roll 7which chills the wax so that the printed wax strip may be immediatelywound into a roll, the printed surface being in opposed relation to awaxed surface as the web of paper is wound into the roll. The waxprevents any offset being taken up by the paper and also removes thetendency to offset as the wax does not have an afiinity for the ink.

The second step of my method, as described in my above mentionedapplication, consists of passing the paper from the roll 3 through aparamn bath 8 between the squeeze'rollers 9 into a chilling bath 10 fromwhichthe roll is passed over suitable guide rollers to the final roll11.

In the passage of the printed web through the paraffin bath 8 the offsetpreventing wax is melted oil the strip and a new coating of wax applied,with the result that the strip is uni- Serial No. 522,989

(Cl. Mill-4116) formly wax coated on both sides and without offsetting.

My improved method is very effective in'preventing ofisets and resultsin a very substantial economy as the printing and rewinding operationmay be very rapid, and there is a great saving in make-ready, that is,it is not necessary to exercise great care in the make-ready to avoidconditions which in ordinary practice would result in objectionableoffset. Further, my improved method renders it practical tosatisfactorily use lower grades of ink than it is possible to use underthe old method.

A further advantage is that less skill is required on the part ofprinters and workmen.

I have illustrated the manner of carrying out my method mainly inconventional form, but it is believed that this will be found sufiicientto enable those skilled in the art to adapt it to particularinstallations and conditions.

Having thus described my invention what I claim as new and desire tosecure by Letters Patent is:

1. The method of preventing offset in printing consisting of printing aweb of paper, applying a substantially continuous coating of liquidparaffin exclusively to the reverse side of the web, and next chillingby passing the paraffined side over a cooling roller, and winding into aroll.

2. The method of preventing offset in printing consisting of printing aweb of paper on one side, applying a substantially continuous coating ofliquid parafhn exclusively to the unprinted side, and next subjectingthe paraflin to a cooling medium, and rolling the paper upon itselfwhereby the printed surface is brought into contact with the paramnedsurface.

3. The method of preventing offset in printing 95 consisting of printinga web of paper, applying a substantially continuous coating of liquidparaffin exclusively to the reverse side of the web, and next chillingbefore substantial penetration of the paper by the paraffin, and rollingthe web of paper upon itself whereby the printed surface is brought intocontact with the paraffined surface.

EDWARD C. FRANCOISE.

